Compounding rubber with powdery substances.



TED STATES. arana curios.

'WILBUR CLARK KNOWLTON AND HARRY A. HOFFMAN, OF AKRON, OHIO, ASSIGNORSTO THE B. F. GOODRICH COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEWYORK.

GOMPOUNDING RUBBER WITH I'OWDERY SUBSTANCES.

Be it known tha-t iWe, W1LBUR CLARK KNowL'roN and HARRY A. HOFFMAN,citizens of the United States, residing at Akron,

in the county of Summit and State of Ohio,

-have invented certain new and useful Imexisting as an impalpablepowder, our object being to keep the atmosphere in the vicinity of themixing mill substantially free from the dust or powder, thus preventingwaste and enhancin the comfort of the operatives. Instead of usmg thelampblack in its natural'condition, we prepare and treat the fine powderso as' to cause its concretion into friable grains or small lumps, dryand substantially free from dust, and in this form incorporate it withthe rubber on the roller mill or in any suitable masticatin apparatusheated in the usual way to so ten the rubber, the friability of thelumps or grains permitting a uniform distribution of the fillerthroughout the rubber. We may use water or other volatile liquid aloneas a concreting agent, first mixing enough of it with the lampblack toroduce the desired condition, and then drying the mass before mixing itwith the rubber, or we may use a liquid binder composed of water and asmall quantity of a soluble agglutinant such as glue, starch, dextroseor sugar, or w some binder insoluble or only partly soluble in water,but miscible therewith and having a tendency to hold the particles ofthe material together in the desired form, the binder remaining in thelampblack after evaporation of the water but not bein present insufficient quantity injurious y to affect the qualities of the rubbercompound.

By way of example, we may take by weight, 240 parts of lam black, 1000parts of hot water and 5 parts 0 starch, the starch I Specification ofLetters Patent.

Patented Nov. 26,1918.

1 Ap'iilication filed August '28, 1917. Serial No. 188,598. I;

being first dissolved in the water and the solution then thoroughlymixed with the lampblack, after which the resulting aste or syrup isdried iii shallow evaporating pans and the material is then ready foruse. These proportions, however, may be varied within rather widelimit-s.

We do not claim broadly the granulation of the powder with a volatileliquid before mixing with the rubber, our invention being an improvementupon the process of that nature described in application of William C.

'Geer, Serial No. 100,153, filed May 26, 1916.

We claim:

1. The method of compounding a plastic substance with an impalpablepowder which consists in causing a concretion of the powder into dry,granular 0r lumpy form, and then mixing it with the plastic substance.

2. The method of compounding rubber with a substance normally existingas an impalpable powder which consists in wetting the powder and dryingit to produce a friable, granular Or lumpy condition, and incorporatingthe dry, granular substance with the rubber.

3. The methodof compounding rubber with lampblack which consists inwetting the powdered lampblack to concrete it, and drying the same,bringing it to a condition of friable grains or lumps, and incorporatingthe dry, granular lampblack with the ru her on a heated mixing mill.

4. The -method of' compounding rubber the lampblack with water,evaporating the water, leaving the lampblack in a granular Or lumpycondition, and then mixing it with the rubber.

5. The method of compounding a plastic substance with an impalpablepowder which consists in mixing the powder with a concreting and bindingliquid, drying the same,

producing a condition of friable grains or lumps, and mixing it with theplastic substance.

6. The method of compounding rubber with lampblack which consists inmixing the lampblack with water and a binder, evaporating the water,producing a condi- Q eeaoae tion of friable grains or lumps, and mixingular lampblack with rubber on a heated said grains or lumps with therubber. mixing mill.

7. The method of compounding rubber In testimony whereof we havehereunto 10 with 'lampblack which consists in mixing set our hands this24th day of August, 1917. 5 the lampblack with water and a binder,producing a granular condition, evaporating WILBUR CLARK KNOWLTON. thewater, and incorporating the dry, gran- HARRY A, HOFFMAN.

